Type bar mechanism for typewriters with segment shift device



1952 J. F. WUNDERLICH ETAL ,3 9

' TYPE BAR MECHANISM FOR TYPEWRITERS WITH SEGMENT SHIFT DEVICE Filed Feb. 24, 1949 2 SHEETSSHEET l Inven for:

JOHANN FRIEDRICH WUNDERLICH OTTO BRANDENBURG b v Filed Feb. 24, 1949 WITH SEGMENT SHIFT DEVICE JOHANN FRIEDRICH WUNDERLIOH OTTO BRANDENBURG Patented Jan. 15, 1952 TYPE BAR MECHANISM FOR TYPEWRITERS WITH SEGMENTSHIFT DEVICE Johann Friedrich Wunderlich and Otto Brandenburg, Nurnberg, Germany, assignors to Firma Triumph-Werke Germany Niirnberg A. G., Nurnberg,

Application February 24, 1949, Serial No. 78,206

' In Germany October 1, 1948 This invention relates to a type bar mechanism for typewriters with segment shift device.

In typewriters with segment shift the transmission of the movement of the key lever to the type bar is effected by a draw bar commotion which is jointed to a bell crank. A special difiiculty in this case is caused by the requirement of uniform key stroke in the normal and shifted position of the type basket. In order to reach this aim, it is known to arrange the bell crank in front of the type rest whereby it is avoided that the free motion of the bell crank when operating the shift device is hindered. This design, however, requires much space for the lever play and, therefore, has an unfavorable effect upon the size and weight of the machine.

In order to avoid this drawback, it has been suggested to arrange the bell crank underneath the type rest. Thus, the bar connection by which the bell crank is connected with thetype bar is shortened and the fulcrum of the bell crank is shifted towards the fulcrum of the type bar.

This arrangement, while resulting in a more compact design of the machine, has the drawback that the key stroke is considerably deteriorated since the joint of the bar connection which is connected to the bell crank, is displaced. This is taken account of by suspending the bar connection in a longitudinal slot of the bell crank, so that it can slide in this slot during the shift motion. This, however, results in an idle motion of the key levers, more particularly in the shift position, since the key lever will operate the bar connection only as it has reached the end of the longitudinal slot of the bell crank. Onlythen the type bar is put in motion, with a rather high speed. This sudden acceleration andthe preceding idle motion when depressing the key lever causes the poor key stroke properties.

A further drawback of this arrangement consists in that owing to the mounting of the bar connection in a longitudinal slot, jarring blows occur which are detrimental not only for the stroke, but also for the speed of typing. Moreover, in case of a high working rate of the machine the slots in the bell cranks will be worn out, whereby the above mentioned drawbacks are substantially increased. Nevertheless in many typewriters all these drawbacks are put up with in View of the more compact design.

It is the object of the present invention to eliminate these drawbacks entirely. I

With this object in view, according to the invention the bracket in which the bell cranks for operation of the type bars are mounted, is mov-' 6 Claims. (0!. 197-27) ably arranged. Thus it is possible to connect the bell crank and the connecting bar with eachother without slot mounting, since the displacement of the bar connection end produced by the shifting is compensated by the movable arrangement of the bell crank. bracket. The movement of the bell crank bracket in this case is controlled indirectly or directly by the shift key, in such a way that the key lever operates always under the same conditions of motion, irrespective of whether the segment shift device is operated or not. To the same end, the joints of the bar connections inserted between the key levers'an-l the bell cranks are disposed in such a way that the angles described by the bar connections on displacement of the bell crank bracket are bisected by the vertical.

The bracket for the bell crank may be mounted in any suitable manner, but it was found particularly advantageous to support this hearing slidably on a roller guide. This bell crank bracket is advantageously acted upon by tension springs and drawn thereby against adjustable stops which define the movement of the bell crank bracket.

Further objects and features of the invention will be seen from the following detailed description in connection with the accompanying drawing, showing by way of example and purely schematically one embodiment of the invention and in which:

Fig. 1 is an elevation, partly in section, of a type bar mechanism according to the invention,

in its normal position; Fig. is an elevation, partly in section, similar to Fig. i, but showing the parts in their shifted position; v

Fig. 3 is a side view of a detail of Figs. 1 and 2,

and

, Fig. 4 is an end View of the ports shown in Fig. 3.

Similar reference numerals denote similar parts in the dififerent views.

Referring now to the drawings in greater detail, it will be seen that i is the type bar segment in which the type bars 3 are mounted at 2. The segment i is screwed to the segment bracket 4 which is swingably mounted on the two arms 5 and 6 which are pivotally mounted in the machine frame at i and 3 respectively, and form a parallelogram guide for the segment bracket 4, so that its upper and lower end positions are arranged just vertically above each other.

Suspended in the type bar 3, at 9, is the bar connection iil whose opposite end is pivotally lever.

connected to the bell crank it, at H. Jointed to said bell crank I2, at 3|, is a bar connection i3 whose opposite end is connected to the key lever M, at 32.

The intermediate lever i2 is pivotally mounted in its bearing 45, at (6, and at both sides bears a bearing bracket i! comprising the adjustable rollers I8 and I9 by which the bearing brackets i! run on guide pins 2!] each secured to the stationary machine part 2|, which moreover on each side of the machine bears an adjustable stop 38.1. a ainst which the bell crank bracket l comes to lie in its normalposition. Moreover a cam lever 23 is swingablv mounted on lever arm 6. by means of a screw 22, so as to be swingable about its fulcrum 8, the roller 25 secured to the bearing bracket i! being adapted to cooperate with the cam path 24 of this cam lever.

A tension spring 26 in its normal position draws the bell crank bracket I5 against the stop The shifting is effected by the shift lever 21 through bar connection 28 acting upon the parallelogram lever 5 acted upon by the tension spring 29.

As shown in Fig. 1, the bell crank bracket IS in its normal position, i. e. with-the shift lever 2! not depressed, lies against the stop 39. under action of its spring 26. As the shift key 21 is depressed, the movement of the parallelogram lever 5 is transmitted to the cam lever 23. Thus the roller 25 secured on bearing bracket I! rolls along the cam path 24 of lever 23, so that the bearing bracket 5! and so the bell crank bracket [5, as shown in Fig. 2, are moved to the right against action of the spring 26. This operation is thus effected by actuation of the shift The fulcrum I5 of the bell crank l2 and so also the point of connection 3| of bar connection I 3 by this movement are displaced to the right by an amount corresponding to the displacement of the point of connection I! of bar connection ill at bell crank l2 owing to the vertical movement of the type bar segment I. Ehese distances are denoted a in Fig. 2.

The joint of bar connection 13 at the bell crank i2 is arranged in such a way that the angle described by the bar connection I3 is bisected by the vertical during this movement. Thus, the

conditions of movement between key lever l4 and bell crank ii. are independent of whether the parts are in their normal or shifted positions.

In this manner any free play in the joints during the striking of a key is avoided and thus a satisfactory type bar stroke is attained which is free from any idle motion.

As various possible embodiments might be .made of the above invention, and as various changes might be made in the embodiments above set forth, it is to be understood that all matter herein set forth or shown in the accompanying drawing is to be interpreted as illus-r trative and not in a limiting sense.

Having thus described our invention, we claim as new and desire to secure by Letters Patent:

1. In a typewriting machine, in combination with a stationary framework and a set of key levers, a set of type bars, a segment bracket on which said type bars are pivotally mounted,

means for vertically shifting said segment bracket suibstantially without horizontal shifting, a bell crank and bar connections jointed between each key lever and its associated type bar, a bell crank bracket on which said bell cranks for actuation of said type bars are. Pl Q' ally mounted, said segment bracket and said bell crank bracket being separately mounted in the stationary framework of the machine, means for supporting said bell crank bracket for shifting, and means for shifting said bell crank bracket under control of the vertical shifting of the segment bracket by an amount sumcient to compensate for the displacement of the bar connection between each bell crank and its associated type bar due to the vertical shifting of the segment bracket.

2. In a typewriting machine, in combination with a stationary framework and a set of key levers, a set of type bars, a segment bracket on which said type bars are pivotally mounted, means for vertically shifting said segment bracket substantially without horizontal shifting, a bell crank and bar connections jointed between each key lever and its associated type bar, a bell crank bracket on which said bell cranks for'actuation of said type bars are pivotally mounted, said segment bracket and said bell crank bracket being separately mounted in the stationary framework of the machine, means for supporting said bell crank bracket for horizontal shifting, and means for horizontal shifting of said bell crank bracket under control of the vertical shifting of the segment bracket by an amount suiiicient to compensate for the displacement of the bar connection between each bell crank and its associated type bar due to the vertical shifting of the segment bracket.

3. In a typewriting machine, in combination with a stationary framework and a set of key levers, a set of type bars, a segment bracket on which said type bars are pivotally mounted, means for vertically shiftin said segment bracket substantially without horizontal shifting, a bell crank for each key lever and associated type bar, a first bar connection jointed between the key lever and the bell crank and a second bar connection jointed between the bell crank and the type bar, the joint between the second bar connection and the bell crank being at a lower level than the joint between the second bar connection and the type bar, a bell crank bracket on which said bell cranks for actuation of said type bars are pivotally mounted, said segment bracket and said bell crank bracket being separately mounted in the stationary framework of the machine, means for supporting said bell crank bracket for horizontal shifting, and means for horizontal shifting of said bell crank bracket under control of the vertical shifting of the segment bracket by an amount sufiicient to accommodate the displacement of the joint between the second bar connection and the bell crank clue to the vertical shifting of the segment bracket, said first bar connection being arranged in such a way that the angle described thereby during the horizontal shifting of said bell crank bracket is bisected by the vertical.

4. In a typewriting machine, in combination with a stationary framework and a set of key levers, a set of type bars, a segment bracket on which said type bars are pivotally mounted, means including a shift key for vertically shifting said segment bracket substantially without horizontal shifting, a bell crank and bar connections jointed between each key lever and its associated type bar, a bell crank bracket on which said bell cranks for actuation of said type bars are pivotally mounted, said segment bracket and means for supporting said bell crank bracket for horizontal shifting, and means for direct control of said bell crank bracket from said shift key for horizontally shifting said bell crank bracket by an amount sufficient to compensate for the displacement of the bar connection between each bell crank and its associated type bar due to the vertical shiftin of the segment bracket.

5. In a typewriting machine, in combination with a stationary framework and a set of key levers, a set of type bars, a segment bracket on which said type bars are pivotally mounted, means for vertically shifting said segment bracket substantially without horizontal shifting, a bell crank and bar connections jointed between each key lever and its associated type bar, a bell crank bracket on which said bell cranks for actuation of said type bars are pivotally mounted, said segment bracket and said bell crank bracket being separately mounted in the stationary framework of the machine, means including a roller guide for slidably mounting said bell crank bracket for horizontal shifting, and means for horizontal shifting of said bell crank bracket under control of the vertical shifting of the segment bracket by an amount suiiicient to compensate for'the displacement of the bar connection between each bell crank and its associated type bar due to the vertical shifting of the segment bracket.

6. In a typewriting machine, in combination with a stationary framework and a set of key levers, a set of type bars, a segment bracket on which said type bars are pivotally mounted, means for vertically shifting said segment bracket substantially without horizontal shifting, a bell crank and bar connections jointed between each key lever and its associated type bar, a bell crank bracket on which said bell cranks for actuation of said type bars are pivotally mounted, said segment bracket and said bell crank bracket being separately mounted in the stationary framework of the machine, means for supporting said bell crank bracket for shifting, and means for shifting said bell crank bracket under control of the vertical shifting of the segment bracket by an amount sufficient to compensate for the displacement of the bar connection between each bell crank and its associated type bar due to the vertical shifting of the segment bracket, said bell crank bracket shifting means including adjustable stop means, spring means tending to pull the bell crank bracket against said stop means, and cam means operated by said segment bracket shifting means and adapted to move the bell crank bracket against the action of said spring means.

JOHANN FRIEDRICH WUNDERALICH. OTTO BRANDENBURG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,161,541 Smith Nov. 23, 1915 1,164,056 Barr et a1 Dec. 14, 1915 1,181,972 Stickney May 2, 1916 2,091,111 Stickney Aug. 24, 1937 

